String tree on a tele style headstock

You don't need xy coordinates. Just somewhere around the D A string tuner, and let the strings dictate the lateral point.​

 

It's around 3 7/16" from the nut on my Fender and G&L. Laterally just do what sissy kathy said...center it over the two strings.

 

The second half has been covered. As for if you need one, try without first and see what happens.

 

Ummm, A string you mean?

The early P basses had them right where the first curve on the bottom of the head begins. Between the A and E tuners. Google 195x precision bass pics.

 

Well, if ya wanna get all correct and everything yes, I do mean the A string. I've been mixing up the A and D for almost fifty years. Why stop now?

 

Pretty sure it went on after the logo and could be put anywhere as long as it didnt cover yhe logo.

 

Here's examples-

 

Remember, when you do it the second time it becomes a tradition and you are obligated to continue doing it. (I learned that at Texas A&M, where it seems to be an inflexible rule.)